Call/message block was a quiet feature added into iOS 7. This gives you the ability to block phone calls, FaceTime calls, iMessages and SMS messages from specific people or companies. Blocking is easy to do and can be done 3 ways.

Phone

If you get a lot of calls from telemarketers then you will love this. Launch the phone app and scroll to the number you want to block. Tap on the "i" next to the number, scroll to the bottom and select "Block this caller". Your phone will never ring with that number again. You will still get voice mails from these callers. They will show up under "Blocked" in your voicemail tab.

Contacts

To block a contact simply open the settings app, scroll to phone, under calls select "Blocked" then tap add new. This will open your contacts and all you have to do is tap on the person you would like to block. This will add any numbers stored under this contact to the blocked list.

Messages

You may have an ex that keeps bothering you or a random number that will not leave you alone. All you have to do is open your messages, tap contact, tap the "i" scroll down to block and tap it. Viola, that annoying person you gave your number to last night is history.

Unblocking a number is just as easy. Open the settings, scroll to phone, select "Blocked", tap edit and remove the number(s) you want.

This feature is super useful for me. I get a lot of garbage calls that I do not want to be bothered with. I added them to the blocked list and I never hear from them again. I have also had to temporarily block some friends that were out of hand with group messaging. This is one of the best new features available in iOS 7.